Figure 3.

Costs of displaying dishonest colour signals of motivation increased with degree of dishonesty. Chameleons painted with bright, aggressive coloration (green line) that did not exhibit aggressive behaviours receive higher levels of physical aggression than those who displayed aggressively. Conversely, those chameleons painted with dark, submissive colours (brown line) that did not exhibit aggressive behaviours received low levels of aggression from their opponents but those who displayed aggressive behaviours while bearing these dark submissive colours received high levels of physical aggression. Solid lines represent maximum-likelihood predictions and shaded regions represent confidence intervals based on 100 000 random samples from the multivariate normal distribution of model coefficients.